Poinsettia care after the holidays

For a vast majority of people Christmas poinsettias are a disposable commodity. There are a few of us however, who adopt them as part of our permanent plant collection.

A while back, for several years in a row, I kept one particularly bright red poinsettia that eventually grew to almost four feet tall. You can imagine it was pretty impressive at Christmas time while in full bloom. Unfortunately, I don’t have any pictures of it to share with you. The computer I was using at the time crashed and took all of my plant photos with it. I learned a hard lesson that day.

To keep your poinsettia going for as long as possible,  keep a couple of things in mind.

Most poinsettias die from over-watering and that is related to growing conditions. Your home probably has a lower quality of sunlight than the greenhouse from which it came, so your plant will be less actively growing and therefore need less water. So, let the soil dry out some before watering. Then water the plant thoroughly until water flows out of the bottom of the pot.

Most poinsettias come with a waterproof foil or plastic wrapper to keep water from leaking onto furniture. After watering, dump out any water that remains in the wrapper. It is this extra water held in the foil that is the main reason poinsettias die prematurely. Poinsettias standing in water develop waterlogged roots. Eventually the roots begin to rot and the plant rapidly declines.

Pour our any excess water that collects in the foil pot wrapper.

Don’t worry about fertilizing your plant, it won’t really need much until spring. A half-strength dose of water soluble houseplant fertilizer once in a while should be more than adequate until growth resumes in the spring.

Also, bear in mind that poinsettias weren’t meant to last too much longer than the Christmas season.  They were bred for color, not hardiness. On the other hand, I’ve seen some poinsettias growing under abysmal growing conditions that survived until spring when the owners set them out in the sunlight to grow again.

At the very least, enjoy your poinsettia as long as possible this winter as a reminder of wonderful Christmas memories.

Bob

Watering a jade plant

This time of the year it’s very easy to over-water house plants.

There is a lot less light in the winter,so most  plants including Jade Plants, will not be as actively photosynthesizing and won’t need as much water.

Over-watering has symptoms similar to under-watering.
When you give a plant too much water, it can cause the roots to become water logged and eventually die back. When the plant loses its roots, it can’t take up enough water, hence, the apparent symptom of not enough water. The well-meaning person taking care of the plant gives it even more water making the problem worse.

A Jade Plant  is able to store water in its fleshy leaves and stems. When it dries out to the point of needing water, the leaves become soft and flexible.

If you think your Jade plant needs water, gently squeeze a leaf or two.

The leaf on this jade plant feels firm, no need to water yet.

If it feel soft, it needs water. If it’s still firm, which in the horticulture trade is called turgid, no water is needed. The plant shown above needs no water, the leaf feels pretty firm.

This next plant’s leaves are soft and flexible, that means this plant needs water.

The leaf on this jade plant feels soft, time to water.

This squeeze-the-leaf  method works only on Jade Plants and other plants with similar fleshy leaves such as sedums and aloe.

Enjoy your indoor gardening!

Bob

Use warm temperatures during January thaw to control insects with water

 

During many winters we have a January thaw. We had a very welcomed warm spell last week and it looks like there will be another warm-up this week too, even though it may not be quite as warm this time around.

I always like to take advantage of those warm mid-winter days to freshen up my house plants and others that I have growing  inside.

Three of my citrus trees, which are about six feet tall including the pot, share space in a southern window in my woodworking area. That means their leaves are often covered in fine sawdust depending on the project I’m working on. I recently finished a project that required quite a bit of sanding which developed a lot of sawdust that settled on the citrus tree leaves.

Last week’s thaw gave me the opportunity to haul out my two wheel hand-truck and wheel out the heavy potted trees out to the driveway. I didn’t need to hose off the plants because of the drenching rain that came later in the day. That rain was all that was needed to get them clean. Since then however, I’ve generated more saw dust and they’re all dusty again.

The good news is that temperatures are predicted to be near 50 degrees F during the next couple of days. That’ll be the the perfect time to wheel them back out and rinse them off again, only this time I’ll have to drag out the hose. Some of my larger house plants are going to get a good outdoor rinsing too.

I rinse my citrus trees every year we have a January thaw. My trees are 17 years old.

This mid-winter rinsing not only washes off dust but even more importantly, it removes many of the small insect and other pests found on indoor plants such as spider mites, mealy bugs and scale. The population of  those types of pests can build up to a damaging level inside a warm, dry winter environment like we have in many Michigan homes this time of year. Rinsing with water knocks back the insect population to a tolerable level.

Mature citrus tree leaves are tough and can handle strong streams of water. Other plants though have more tender leaves which can be bruised by a too vigorous spray from an exuberant gardener — I know, I’ve done it.

If you plan to do a mid-winter rinsing, I suggest you start with a fine spray and increase the pressure if needed.  You’ll have to use your best judgement as you go along. I use a three-hole nozzle that puts out a very fine, yet strong stream of water that knocks off just about everything without damaging leaves. Be sure to spray the under-side of the leaves. That’s where the biggest concentration of pests will be hiding.

Bob

 

 

 

 

 

 

 

Use old camera as light meter for plants

If you are like me, you find it hard to toss or give away any of your really good stuff, even if it is obsolete. I still have my old SLR film camera, a Pentax K1000 that I bought way back when. It was one of the first things that I splurged on during my early adult life when I really couldn’t afford it. That is probably why I feel so attached to it even though I haven’t taken any photos with it for many years.

There is however another alternate use for that old camera of yours still bumping around in your closet. It can be used as a light meter to determine the amount of light available in the spots where you are planning to keep your plants indoors during the winter.

20171207_113118

This method measures the reflected light from an area as opposed to some light meters that you point at the light source. Set the shutter speed to 1/60 and the ASA to 25. Take a sheet of white paper and place it in the spot you want to measure. Point your camera at the paper and look through the viewfinder. Move so that the white of the paper is the only thing you can see in the viewfinder. Follow the meter inside the view finder and adjust the f/stop until the the meter is in the optimum range for taking a photo. From there you can use the f/stop to get a fairly good approximation of foot candles (fc): f/2 equals 40 fc; f/2.8 =75; f/4=150 fc; f/5.6=300 fc; f/8=600; f/11=1200 fc; f/16=2400 fc. Each f/stop move indicates a doubling of  foot candles from the previous setting. If you own an older camera like this you probably remember what ASA and f/stop means, everyone else will have to look it up.

Foot candles reading below 75 is considered low light. Readings up to 200 fc is moderate light while anything over 300 fc is bright light. That will give you some idea where to place which plants over the winter.

Now, if only I can figure out how to blog using my manual typewriter.

Bob

 

 

 

Mother’s day plant sale at Matthaei Botanical Gardens this weekend

The Matthaei Botanical Gardens – Nichols Arboretum annual Mother’s Day Plant Sale is coming up this weekend, May 13 and 14.

About three weeks ago I visited the Gardens and got a sneak peek at the plants growing in the greenhouse. I can tell you that these are no ordinary, anonymous plants grown by an impersonal factory growing operation. They are lovingly grown and tended by Adrienne O’Brien and her helpers right in the greenhouse at the Botanical Gardens. When I was there, the plants were still young but were growing strong and looked absolutely wonderful.

Horticulturist Adrienne _________ leads team of plant grower at Matthaei Botanical Gardens - Nichols Arboretum
Horticulturist Adrienne O’ Brien leads her team of plant growers at Matthaei Botanical Gardens – Nichols Arboretum.

 

A month ago Adrienne was worried that the plants were ahead of schedule.
A month ago Adrienne was worried that the plants were ahead of schedule.

Now the plants are ready to go home to Mother’s house.

The plants will be sold in the same greenhouse that they were grown in.
The plants will be sold in the same greenhouse that they were grown in.
Wide variety of beautiful hanging baskets
Wide variety of beautiful hanging baskets
Container plants make a great gift for Mom on Mother's Day.
Container plants make a great gift for Mom on Mother’s Day.
Whimsical planters like these are lots of fun.
Whimsical planters like these are lots of fun.

 

The sale runs from 10:00 am to 4:30 pm both days (9:00 am if you are a member). Matthaei Botanical Gardens is located at 1800 N. Dixboro Road, south of Plymouth Road, Ann Arbor.

Bob

Why does a jade plant bloom?

One of our jade plants has started blooming this week. Anyone with a jade plant knows this is fairly uncommon. I have had a few jade plants through the years that produced flowers but not very many. So whenever it happens, I get a little excited about it.

Jade plant flowers are white with a pink hue near the edges and are about 3/4 inch across.
Jade plant flowers are white with a pink hue near the edges and are about 3/4 inch across.

There seems to be no way of predicting when a jade will blossom. Lots of people, horticulturists included, have their theories about it. Some folks on the internet say they have it figured out. If that were the case, we’d be seeing truckloads of jade plants in the stores blooming just in time for Mother’s Day or Valentine’s Day — pick your favorite holiday.

Flower production in plants can be a complex proces. Before a plant can flower, it has to go through several steps before vegetative cells change into  reproductive cells, ie. a flower bud.

A basic principle in botany is that a plant, like most other organisms, will not reproduce until they reach maturity. One familiar example of this is an apple tree which might not bloom for six or eight or even ten years.

We forget sometimes, that our houseplants’s ancestors originally grew out in the wild with no help from people, thank you very much. Jade plants belong to the genus of plants called Crassula. Many Crassula species go through an annual a rest period in their native habitat. In their part of the world, the rains stop for a while and the Crassulas  go into a rest period. It’s critical for the Crassulas that the humidity falls to an arid, desert-like condition during this time.

Once the dry period is over, the plants resume growing and that completes one lifecycle. So, to induce flowering, it would make sense that we try to reproduce those types of conditions found in the wild.

OK, so here is my theory of the erratic flowering of jade plants. Many gardeners or houseplant fanciers love their plants and don’t want to hurt it, I don’t blame them. So they keep watering and feeding the plant all year ’round which keeps the plant in a continuous growth stage. The jades never get a chance to rest and they never get a chance to complete a full annual life cycle. This either delays maturity or fails to trigger the reproductive response.

Many factors are involved in stimulating plants to flower: fertility, moisture, intensity of sunlight, length of daylight, temperature extremes both warm and/or cold, length of time exposed to temperatures, air movement, insect damage, and others. The timing of all or any one of these factors can determine if and when a plant will bloom. Some easy-blooming plant species will bloom despite not growing in ideal conditions. Others, like jade plants I’m guessing, require a more complex sequence of events in order to produce flowers.

All that being said, I have noticed that jade plants are more likely to bloom is they are slightly pot-bound. So does this mean that the plants have been growing long enough that they’ve reached reproductive maturity? Or does crowding their roots induce flowering? Maybe sometime in the future a budding horticulturist will discover the secrete.

Bob